A "Nothing Better to Do" one afternoon project

[amlevin]

We've all heard all the comments on how Factory Ammo is so lousy when it comes to accuracy. It's essentially the "Mantra" of all reloaders/handloaders out there that tout the superior accuracy of their special load.

Some of this is correct as every rifle has its own peculiarities when it comes to launching a bullet on its path.

But then there is the consistency of manufacture that is also a part of the equation.

For some dumb reason I bought a box of Federal ammo for my .308 which was loaded with 180gr. Trophy Bond bullets (kind of a Barnes "clone"). To put it bluntly, they shot like <deleted>. The 100 yard Group, if you want to call it that, looked more like a shotgun pattern using 00 Buck at 50 yards. I was shooting from a bipod with accushot monopod on the buttstock, the same setup that regularly shoots >1/4" groups at the same distance. Needless to say I tossed the box in my "someday I'll use this up" stash.

The other day I had nothing better to do and took 10 of these rounds apart to see what made them tick. Using a Forster collet type puller I pulled all bullets and carefully weighed the powder. The collet type puller allowed me to collect every granule of powder (which was a fine ball type, similar to AA2230) so I could get accurate weights. I weighed the collected powder, one load at a time, on a freshly calibrated RCBS Digital Scale (part of my Chargemaster Combo).

Here are the results:
Cartridge # +/- average
41.1 gr. -.06 gr.
41.4 gr +.24 gr.
41.2 gr +.04 gr.
40.8 gr -.36 gr.
41.4 gr +.24 gr.
41.3 gr +.14 gr.
41.1 gr -.06 gr.
41.0 gr -.16 gr.
41.3 gr. +.14 gr.
41.0 gr. -.16 gr.

Average powder Weight= 41.6 Gr.

Extreme Spread Powder Weight = .6 grains

So much for Federals claims to accuracy and such. This spread of weights would easily yield as much as 100 fps by my guess, depending on the exact powder type. The advertised speed was 2620 fps for this ammo but I wonder just how accurate that is considering the spread in their powder weights.

Like I said in the beginning, I didn't have anything better to do that afternoon. At least now I have 10 primed cases and 10 180 gr bullets that I can load a heck of a lot more accurately than Federal can.

 

[kingmt]

You could always load them back up at 41.6gr & see if they do any better. +/- .3gr doesn't seem that drastic I'm surprised they shoot that bad. When I'm working up a load I don't usually see that much of a difference in 2.0gr.

I have a 30-06 that I haven't found a load yet that works better then Hornady Custom 165gr. I'm going to keep trying though.

 

[amlevin]

kingmt

That's .3 gr from average. The extreme spread is .6 gr.

Just for the sake of conversation, if every .1 gr gave a 1/4" variation in group size, it would only give this group a radius of 3/4". Unfortunately the diameter of the group would be 1-1/2" for this hypothetical group size.

In reality it was more than 3".

As for loading up with the factory powder, I've got a recipe for Varget that works great with 180 gr. bullets. I just tossed the factory powder on the yard.

 

[john16443]

Did you save the bullets and have a chance to weigh them? Would be interested in knowing the range associated with the bullets, and then the same information for the factory cases.

 

[kingmt]

I really don't know what kind of a pattern buck @ 50yd I guess I was expecting more then 3". My test loads norm is about 3" with a 3gr spreed from min to max.
41.2 is your average but 41.3 is the center of the extreme spread ether way it's about +/-0.3gr.

I believe you just surprised they are that bad.

Is this a bolt gun or a auto? I assume bolt with 1/4" @ 100.

I'm also interested in what you know about the bullets.

 

[kelbro]

Looks like the average is 41.16 and the standard deviation is 0.2. Not too shabby.

 

[murf]

toss the bullets. trophy bonded anything is not a target bullet. you want small groups, get bergers or sierra matchkings, or something. it is definitely not the powder weight variation. imop

murf

 

[ranger335v]

"if every .1 gr gave a 1/4" variation in group size, it would only give this group a radius of 3/4". "

Interesting thought but the premise of your statement has no certain validity in fact. It is quite possible that a .6 gr. charge spread wouldn't be seen at 100 yards and it may not be seen inside 300 yards. And surely no one would seriously plan to use factory ammo for 300 + yard competitions or hunting without range tests first so... ??

That isn't a target bullet, the ammo isn't marketed for target shooting. All you've really 'proven' is that your rifle doesn't like that load. Your poor accuracy is likely due to your rifle simply not liking that bullet rather than any blanket poor performance of it or Federal ammo, as such. Anyone with much experience reloading knows some rifles love some bullets while others don't and there's no way to predict which way it will go! And do some identical testing, pulling and measuring on other brands before getting too critical of one box of Federal!